Abstrict An adjustment mechanism for a rock crusher has an insert installed
in the thread form of a bowl support and a locking ring. A bowl
is threadably installed in the bowl support and lock ring assembly
and is movable toward and away from a cone assembly. The insert
is of a material that differs from that of the bowl and bowl support.
The lock ring is movable to frictionally lock the thread forms of
the bowl and bowl support against each other. The inserts prevent
the galling and deformation of the thread forms previously experienced.
Claims What is claimed is:
1. A rock crusher comprising:
a conical shaped bowl, a cone mounted for oscillating movement
within the conical shaped bowl, said bowl being vertically adjustable
relative to the cone for crushing rock to specific sizes;
a frame including an annular bowl support, said bowl adjustably
supported within said annular bowl support for vertical adjustment
of the bowl relative to the cone;
said vertical adjustment provided by mated screw threads on said
support and said bowl, the screw threads on one of the support and
bowl provided by a recessed thread form that is spaced from and
in non-engaging relation with the screw threads on the other of
the support and bowl, and a thread producing insert seated in said
thread form, said insert projecting from the thread form and into
engagement with the screw threads of the other of said support and
said bowl.
2. A rock crusher as defined in claim 1 wherein the insert is comprised
of a elongated metal strip sized and configured to fit the configuration
of the thread form, said insert being of a material that is dissimilar
than the material of the bowl support and bowl.
3. A rock crusher defined in claim 2 wherein the insert is comprised
of an elongated resilient metal member that is sized and configured
to fit a thread form provided on the bowl, said thread form in natural
state assuming a curved shape having a radius of curvature smaller
than the thread form and which is resiliently forced onto the thread
form to provide a grip-type seating of the insert in the thread
form.
4. A rock crusher as defined in claim 1 wherein the insert is comprised
of an elongated resilient member that is sized and configured to
fit a thread form provided on the bowl support, said thread form
in natural state assuming a curved shape having a radius of curvature
greater than the thread form and which is resiliently forced into
the thread form to provide a grip-type seating of the insert in
the thread form.
5. A rock crusher as defined in claim 1 wherein the bowl and bowl
support, within the region of the thread and thread form and without
the insert seated in the thread form, are sized to provide free
sliding of the bowl through the bowl support, the insert fitted
to the thread form providing the screw-type relationship as between
the bowl and bowl support.
6. A rock crusher as defined in claim 5 wherein the thread form
has a similar configuration to that of the screw thread of the other
of said support and bowl and the insert being diamond shaped to
fit the screw thread and screw thread form.
7. A rock crusher as defined in claim 1 wherein the thread producing
insert is configured along one side to mate with the thread form
and provide removal and replacement without remachining of the thread
form.
8. A rock crusher comprising:
a conical shaped bowl, a cone mounted for oscillating movement
within the conical shaped bowl, said bowl being vertically adjustable
relative to the cone for crushing rock to specific sizes;
a frame including an annular bowl support, said bowl adjustably
supported within said annular bowl support for vertical adjustment
of the bowl relative to the cone;
said vertical adjustment provided by mated screw threads on said
support and said bowl whereby the bowl is screwed up or down on
the support and thereby closer or farther away from said bowl;
an annular lock ring having a screw thread mated to the bowl and
screwed onto the bowl and defining an annular surface in abutment
with an annular surface of the support;
an annular chamber provided in one of the lock ring and bowl support
and an annular piston fitted to the chamber, said piston providing
the abutment surface for one of said lock ring and bowl support;
and
a hydraulic fluid source providing hydraulic fluid to the chamber,
and a control for controlling the hydraulic fluid flow to the chamber
for urging movement of the annular piston toward the surface of
the other of the lock ring and support and thereby producing a binding-type
lock that inhibits screw movement of the bowl.
9. A rock crusher as defined in claim 8 wherein the piston is provided
with a seal portion between the piston and hydraulic fluid and expands
under pressure to seal the chamber and induces movement of the piston
against the other of the lock ring and bowl support.
10. A rock crusher as defined in claim 9 wherein the annular chamber
is provided in the lock ring.
11. A rock crusher as defined in claim 8 wherein the screw threads
on the support and the lock ring are provided by thread forms and
inserts seated in said thread forms, said inserts projecting from
the thread forms and providing the entire screw thread surfaces
in mated engagement with the thread of the bowl.
Description FIELD OF THE INVENTION
This invention relates to a cone-type rock crusher wherein a crushing
cone gyrates inside a bowl and crushes rock fed between spaced apart
mated surfaces of the bowl and cone, and more particularly it relates
to the mechanism for adjusting the spacing between the cone and
bowl.
BACKGROUND OF THE INVENTION
A cone-type rock crusher crushes large sized rock retrieved from
a rock quarry into small sized rock used for road beds and the like.
The demand for the small sized rock varies between, e.g., one inch
diameter rock, one-half inch diameter rock, etc., depending on the
application. The rock crusher is preferably adjustable to crush
the rock into the different sizes and in any event, due to wearing
of the liner that provides the mating surfaces between the bowl
and cone, the size of rock produced at a particular setting will
over time increase in size and accordingly the rock crusher needs
to be adjustable to accommodate the wearing of the liner.
There are several different types of mechanisms used for achieving
this adjustability. Basically the adjustment amounts to raising
or lowering the bowl of the crusher relative to the cone. The bowl
is mounted to a bowl support of the main frame of the crusher and
adjustment is a matter of raising or lowering the bowl as mounted
to the frame. One type of mounting provides for vertically positioned
bolts that bolt the bowl to the frame. Shims are transferred to
positions on the bolt above or below the bowl connection to lower
or raise the bowl. Hydraulic cylinders are also used. The type of
mounting contemplated for the present invention, however, uses screw
threads.
The bowl is provided with screw threads on an exterior circumference,
which engage screw threads provided on an interior circumference
of the bowl support of the frame. The bowl is simply screwed down
to the desired spacing over the cone and then locked in place. When
adjustment is desired, the locking mechanism is released and the
bowl is screwed up or down to the desired position and re-locked.
The screw-type adjustment is preferred in the respect that the
bowl is thereby rotated and changes the position of the liner circumferentially.
Whereas the cone liner rotates (slowly) during the crushing operation,
the bowl liner is held fast during a crushing operation. Screw-type
adjustments achieve rotational repositioning of the bowl liner and
avoids undesired wearing in a particular location of the liner.
The challenge for such screw adjustment is to achieve and retain
the ability to turn the bowl on its threads. The threads are necessarily
of large pitch, e.g., 2 inches, and the mass of the bowl produces
large compressive forces between the engaged thread surfaces. Experience
has taught that relative movement between such surfaces produces
galling of the surfaces and the heat generated from such movement
can weld the surfaces together and thereby prevent further turning.
A further problem is the requirement that during the rock crushing
operation the bowl must not be allowed to move on its threads. A
lock ring is used to create binding of the threads and prevent turning,
but the conventional cinching down of the lock ring (which simulates
the well known lock nut) to produce such binding is not suitable
for the forces involved in a rock crushing application. Heretofore
the lock ring has incorporated a plurality of circumferentially
placed hydraulic rams that generate the desired binding and locking
of the screw threads. Such has not been found satisfactory and the
present invention serves to provide an improved mechanism for achieving
this binding action.
BRIEF SUMMARY OF THE INVENTION
Referring first to the problem of the screw threads being welded
to prevent desired turning, reference is made to a proposed a solution
disclosed in U.S. Pat. No. 4571112. This patent teaches the provision
of grooves in a load bearing surface of the screw threads and low
friction inserts set into the grooves but projected outwardly of
the screw thread surface. The force of the opposing thread surface
is therefore applied against the inserts and not the screw thread
surface having the inserts. The inserts being a dissimilar material
and having a low co-efficient of friction, facilitates turning of
the bowl relative to the frame.
However, the load of the bowl is thereby concentrated on the surface
areas of the inserts which is substantially less than the thread
surface. The inserts rapidly wear and due to inherent limitations
as to the extent that the inserts can project out of the surface
of the screw threads, the projected portion of the inserts will
rapidly wear away and allow the undesired face-to-face engagement
between the screw threads. Also, because of the smaller engagement
surface of the inserts abutting the opposing screw thread surface,
the inserts can produce some galling of the opposing screw thread
surface. Still further, replacement of the inserts often requires
re-machining of the groove, a task difficult to achieve "in
the field".
Applicant's solution is to essentially provide complete replacement
of the screw threads of one of the bowl and frame with a low friction,
dissimilar material referred to as a thread replacement or thread
producing insert. In the preferred embodiment, the circumferential
surface of the selected component is sized to be set back or clear
of the screw threads of the non-selected component. Grooves are
formed in the circumferential surface (which may resemble a screw
thread and is here referred to as a screw thread form) and elongate
thread producing inserts are placed in the grooves. The inserts
project from the grooves and are configured to form the screw thread
of the selected component. The entirety of the insert projected
from the thread serves as the engagement surface for the opposite
screw thread. The inserts are easier to assemble into the selected
component and the wearability is increased many times over that
of the prior art.
Additionally, the thread producing inserts are resilient and formed
into curved springs that are oversized in radius if intended for
the exterior component (bowl support) and undersized if intended
for the interior component (bowl). Forcing the spring-like inserts
into the grooves produces a spring force that induces seating of
the inserts in the grooves. Movement of the inserts in the grooves
is prevented by inserting lock pieces at the extreme upper and lower
ends of the seated inserts (multiple inserts typically making up
a complete screw thread). Replacement in the field can be readily
achieved without re-machining the thread forms and thus far more
easily than the strip inserts of the prior art.
A similar insert is preferably applied to the locking ring. Locking
of the bowl to the bowl support (frame) as required for the crushing
operation, is provided by an annular seal and piston. An annular
cavity is provided on the under side of the ring and the annular
seal and piston is fitted to the cavity. A space above the seal
and piston and within the cavity provides an expansion chamber.
Hydraulic fluid pumped into the chamber forces the piston, e.g,
against the frame with the lock ring screwed onto the bowl to generate
the desired binding force. The annular piston produces the desired
force consistently around the entire circumference.
The invention and its application to the preferred embodiments
will be more fully appreciated upon reference to the following detailed
descriptions and drawings referred to therein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in cross section of a cone-type rock crusher;
FIGS. 2A, 2B and 2C are views of a bowl support of the crusher
of FIG. 1;
FIG. 3 is a view of a bowl of the crusher of FIG. 1;
FIGS. 4A, 4B and 4C are views of a locking ring which locks the
bowl to the bowl support; and
FIG. 5 is an enlarged partial view of the thread engagement between
the bowl and bowl support as viewed in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a portion of a cone-type rock crusher 10. The
crusher 10 has a cone assembly 12 which rotates about a vertical
axis 14 in an gyrating manner. A bowl 20 is adjustably mounted on
the crusher 10 and is adjustable toward and away from the cone assembly
12. The bowl 12 is adjusted toward or away from the cone assembly
12 to adjust the closed side setting between the bowl 20 and the
cone assembly 12. The cone assembly 12 has a replaceable liner 16
and the bowl 20 has a replaceable liner 22. During normal use, the
liner 16 on the cone assembly 12 and the liner 22 on the bowl 20
are subject to wear during the crushing operation. As shown in the
figure, the bowl 20 is adjustable upwardly and downwardly on a bowl
support 30 which is part of the frame of the crusher 10. In this
embodiment, the bowl 20 is threadably installed in the bowl support
30 and the bowl is adjusted toward and away from the cone assembly
12 by rotation of the bowl 20 relative to the bowl support 30. A
lock ring 50 is provided to lock the bowl to the bowl support 30
when it is in the adjusted position.
The bowl support 30 is fixedly mounted to the frame of the machine
and as shown in FIG. 1 the bowl support 30 is mounted strategic
to the cone assembly 12. Referring to FIGS. 2A, 2B and 2C the bowl
support 30 has internal thread forms 32 formed on its interior surface.
The bowl support 30 has a radially extending rim 34 for supporting
a locking ring 50 (See FIG. 1). The rim 34 has bores 36 to receive
guide pins that prevent the locking ring 50 from rotating relative
to the bowl support 30.
The bowl 20 as seen in FIG. 1 is sized to fit within the bowl support
30 and is adjustably movable upwardly and downwardly toward and
away from the cone assembly 12. The bowl 20 (best seen in FIG. 3)
has an external thread 24.
The lock ring 50 (FIGS. 4A, 4B and 4C) is circular in configuration
and has internal thread forms 52 that are of the same configuration
as the thread forms 32 of the bowl support 30. The lock ring 50
is mounted to the bowl support 30 as shown in FIGS. 1 4B and 5
by pins 54 fitting through the bores 36 of the bowl support and
threadably installed in a threaded bore 56 in the lock ring 50.
The pins 54 prevent rotation of the lock ring 50 relative to the
bowl support 30. The pins 54 are not tightened against the bowl
support 30 and have a sufficient extension from the bowl support
30 to permit the lock ring 50 to be restrictively moved upwardly
away from the bowl support 30.
The lock ring 50 has an annular groove 58 which serves as a cylinder.
(See FIGS. 4A and 4B) An annular ring (piston) 59 is fitted to the
annular groove 58 with the piston 59 being in abutment with the
rim 34 of the bowl support when the lock ring 50 is installed on
the bowl support (See FIGS. 2A and 2C). As seen in FIG. 4B, a seal
portion 59a is separate from the piston but forms a complimentary
part of the piston. Seal portion 59a has side flanges 61 and a central
cavity receiving O-ring 63.
Ports 80 are provided in the lock ring (FIG. 4B) to supply hydraulic
fluid to the cylinder 58. A hydraulic line 82 extends from the port
80 to a hydraulic source 84 (FIG. 1). Hydraulic fluid acting against
seal portion 59a induces bulging of the flanges 61 to prevent fluid
from getting past the seal portion and then downward movement of
the seal portion 59a and the underlying piston 59.
Inserts 60 are installed in the thread form of the bowl support
30 and the lock ring 50 (FIGS. 2A and 4B). The inserts 60 in this
embodiment are of a brass like resilient material which differs
from the material of which the bowl support 30 and the lock ring
50 are made of. The inserts 60 are formed to conform to the thread
form of the bowl support 30 and the lock ring 50. It is preferable
to form the inserts 60 to a slightly larger diameter than the thread
form of the bowl support 30 and the lock ring 50. The resilience
of the inserts 60 when installed will force the seating of the inserts
60 in the thread form of the bowl support 30 and the lock ring 50.
A stop piece 62 is fixedly mounted in the thread form of the bowl
support 30 as illustrated in FIG. 2B. The stop piece 62 is fixedly
mounted to the thread form as by welding. The stop piece 62 will
prevent the insert 60 from moving in the thread form 32.
In this embodiment multiple lengths of inserts 60 are installed
in the thread form 32 of the bowl support 30. The lengths of the
inserts 60 are generally of a length that is commercially available
(i.e., 12 feet). The first insert 60 is placed in the thread form
32 with an end of the insert being abutted against the stop piece
62. The inserts 60 being formed to have a slightly larger diameter
than that of the thread form 32 will, due to its resilient spring
action, be forced to seat in the thread form 32. The next insert
60 is installed with one end of the insert being in abutment with
the end of the first insert. Additional inserts 60 are installed
until all of the fully formed threads 32 are filled. When all of
the inserts 60 are installed, the inserts are forcibly moved toward
the stop piece 62 to insure that the inserts 60 are fully abutted
against an adjacent insert. Another stop piece 64 is abutted against
the end of the last insert 60 and is fixedly attached to the thread
form 32 as by welding.
Inserts 60 are fitted to the thread form 52 of the lock ring 50
(FIG. 4B) in the same manner as installed in the bowl support 30.
Stop pieces 62 and 64 are fixedly mounted to the thread form 52
to secure the inserts 60 in position. It is preferable that the
inserts 60 extend at least 360 degrees around the lock ring 50.
Refer again to FIGS. 1 and 5 of the drawings. The lock ring 50
is mounted to the bowl support 30 and is retained in position by
pins 54. The bowl 20 is threadably installed to the assembly of
the bowl support 30 and the lock ring 50. The thread form 24 of
the bowl 20 will be engaged with the inserts 60 of the bowl support
30 and the lock ring 50.
A known drive mechanism, generally indicated by 70 in FIG. 1 rotates
the bowl 20 relative to the bowl support 30 (and lock ring 50) to
cause axial movement of the bowl 20. When the bowl 20 is rotated
in one direction, the bowl 20 will be moved along axis 14 toward
the cone assembly 12. When the bowl 20 is rotated in the opposite
direction the bowl will be moved along axis 14 away from the cone
assembly 12.
When the bowl 20 has been adjusted to be at the desired distance
from the cone assembly 12 the bowl 20 is locked in position relative
to the bowl support 30 by the lock ring 50. Hydraulic pressure is
applied to the cylinder 58 which forces the seal portion 59a and
thus piston 59 against the rim 34 of the bowl support. This forces
the lock ring 50 upwardly away from the bowl support 30 which forces
the insert 60 received in the thread form 52 upwardly against the
thread form 24 of the bowl 20. This action "locks" (binds)
the thread form 24 of the bowl 20 against the inserts 60 in the
thread form 32 of the bowl support 30 and prevents rotation of the
bowl 20 relative to the bowl support 30.
The insert 60 has been illustrated as being substantially square
or diamond shape in section. It will be appreciated that other sectional
forms such as circular, triangular and others may be utilized as
an insert. The thread forms can also be differently configured as
long as the inserts are correspondingly configured to fit the thread
forms. Also it is contemplated that the inserts may be fixedly mounted
to the thread form of the bowl instead of the bowl support. In this
case, it may be desirable that the curve of the insert is undersized
to provide the desired gripping. Other fastening methods may be
employed to maintain the insert 60 in position such as adhesive
bonding, threaded fasteners and the like. Another variation is to
provide the chamber 58 seal portion 59a and piston 59 in the bowl
support 30 e.g., in a modified version of rim 34 against which
the lock ring is abutted.
Those skilled in the art will recognize that the modifications
and variations may be made without departing from the true spirit
and scope of the invention. The invention is therefore not to be
limited to the embodiments described and illustrated but is to be
determined from the appended claims. |